I am currently using early reflections to add width and space to my recordings. I have to say it's been very eye opening and I'm still very new to it, but it seems to be helping. My current method is using a mono delay plugin (H-Delay) panned hard left and right, with no feedback, making the ms delay slightly different on each side (about 20ms, and 30 ms respectively). I'll then send everything that needs to be more 'up front' to these busses, and usually put just a bit of it on everything to unify things. Then I'll compress those delays and heavily low pass and high pass them so they're just mostly mids.

My question is, is this the best technique? What do you guys use? One ambient reverb in stereo that is wide and tight and short could probably accomplish the same thing, I suppose. Is the HPF and LPF the way to go? When I compare my "closeness" and "width" of the initial ambience of my mixes they still don't sound as wide of a room as professional recordings I like. Does increasing the delay time (say up to like 80ms) change the depth of the room?

Also, do you put ER on already existing reverb sends?

Any tips on this are very much appreciated, as I'm still very new to this and I feel it's pretty crucial - if it's about what you put it on, how you set it up, if you only put it on vox and drums, or whatever is louder, or if the filters are a bad idea, etc etc.

TLDR How do you set up your ER busses, and how do you integrate them into your mix as far as your chain, what you apply the ER on to, and what to listen for. Do you put your reverb busses through a ER first as well as the dry instrument signals, or is that redundant and cluttering?